This invention relates to a novel sewing machine attachment and, particularly, to an attachment for holding an accessory, such as a hook or an eye, in a predetermined position for sewing. The sewing machine or stitch-forming machine used for the novel attachment hereinafter described is of the type generally used to secure buttons, hooks or other fasteners to fabric or other pliable web material.
U.S. Pat. No. 3,143,092 issued Aug. 4, 1964 to A. Glassman et al discloses a sewing machine attachment for use in locating and holding a magnetizable accessory in a predetermined position for sewing on a sewing machine. That attachment comprises generally (a) a substantially horizontally-extending positioning member having an open cavity therein wherein at least a portion of the walls of the cavity defines a seat for an accessory and (b) magnetic means within the positioning member for producing a magnetic flux which extends from said seat through the opening in the cavity. U.S. Pat. No. 3,415,210 issued Dec. 10, 1968 to A. Glassman discloses another such sewing-machine attachment.
Previously, the horizontally-extending positioning member was made by milling out a deep groove in a block of brass or other nonmagnetic material and then soldering a plate to the block thereby forming the cavity in which the plate is the bottom major wall of the cavity. In use, the plate is the most frequent site of failures. For example, while sewing, when the needle strays from its normal path of travel, it often strikes the accessory whereby it pushes down causing the solder joint to rupture and the plate to burst away from the attachment.
Another problem with the prior attachment is that dust and foreign particles accumulate in the cavity and are compacted at the back of the cavity adjacent the source of magnetic flux. The compacted debris interferes with the operation of the attachment and often prevents the accessory from seating properly. The prior attachment is provided with a clean-out hole which can be used for removing the debris from the cavity by poking with a wire or other elongated object. While this procedure provides some relief, it is time consuming and is not practiced frequently enough, so that the problem persists and hampers the effective usage of the attachment.